INTRODUCTION

This project is one component of the CEAP program of Calvin College, fall semester 1998. The objective of this particular study was to determine the water quality of various input channels which discharge into Ravenswood and President's Ponds. These two ponds are located to the north of Calvin's campus, immediately south of Lake Drive. During episodes of precipitation, President's and Ravenswood ponds received drainage water from residential areas in East Grand Rapids, and theathletic fields and parking lots on the Calvin College campus. An initial survey revealed three main channels, which discharged significant amounts of storm runoff

1) a drainage ditch form Calvin's north parking areas, baseball diamond, and peripheral houses which flows north into Ravenswood,

2) a discharge outlet of the East Grand Rapids storm sewer which joins the first channel as it empties into Ravenswood pond,

3) an outlet delivering drainage from Calvin's soccer fields into President's pond. Rainwater is channeled under an access road and flows down a gully, where it intersects a narrow cattail stand and enters the pond.

The assessment of water quality in this study was based on tests for ammonia, nitrate, Total hardness, chloride, Total alkalinity, and phosphate. The phosphate content of the input channels was of particular interest. Phosphate is a limiting agent for plant growth, and is a major component of commercial fertilizers. The eutrophic condition of Ravenswood and President's ponds suggests that phosphate is present as a contaminant. Thus a major goal of this project was to determine where and at what levels phosphate is delivered to the pond system.

Chloride was also thought to be a possible pollutant in the input channels. "Road salt," used for melting ice in winter, can stay in the surrounding soil and be readily leached from the substrate during storm activity. High chloride levels add to the salinity of standing water. It was initially thought that the highest level of chloride in the inputs would be expressed in the storm sewer from East Grand Rapids.

METHODS

Five sites were chosen to sample the input channels to the ponds (Fig. 1). Site number one sampled directly from the drainage ditch south of Ravenswood pond. At site number two, stormwater was sampled as it ran out of the culvert of the East Grand Rapids storm sewer, and site number four corresponds to a outlet pipe from the soccer field drainage. Site number three was chosen to investigate the combined channels of sites one and two as they enter Ravenswood pond. Site number five was also selected in order to gain insight as to how water chemistry was altered between its expression at the ground surface and its incorporation into President's pond.

Water samples were taken during episodes of precipitation between September 30 and November 10, 1998 (Fig. 2). These samples were collected in polyurethane Whirl-Paks and were brought back to the lab for analysis.

In the laboratory, the water was tested using procedures and equipment produced by the HACH company. All titrations were performed using the HACH Digital Titrator (Model 16900).

- Phosphate, Ortho (0-50 mg/1) Model Po-19 Cat. No. 2248-00 Lot J82 This test uses Phos Ver 3 Phosphate Reagent as an indicator,

-Chloride (10-800 mg/1) Model CD-DT Cat. No. 20635-00 Lot T8183 Diphenylearbazone titrated with Mercuric Nitrate

-Nitrate (0-50 mg/1) Model Ni-11 Cat. No. 1468- 03 Lot J6242 NitraVer 6 Reagent in color comparator

-Alkalinity (10-4000 mg/1) Model AL-DT Cat. No. 20637-00 Lot J6239 Phenolphthalein Indicator, Bromeresol Green-Methyl Red indicator, titrated with Sulftiric Acid

-Ammonia, Mid Range (0-3 mgA) Model Ni-8 Cat. No. 2241-00 Lot J5278 Nessler Reagent as indicator

-Hardness, Total (10-4000 mg/1) Model HAC- DT Cat. No. 20639-00 Lot T8230 Hardness Buffer Solution, Man Ver 2 Hardness indicator, titrated with EDTA cartridge

RESULTS

The results of the chemical analysis of the water are shown in Table 1. Values were not obtained for site numbers one, two, and four on sample dates September 30 and October 1. These sites were added after the first two collection dates. On October 17, there was no water at site one to obtain a sample. There were no levels of nitrate detected at any of the sites during the sample period.

The mean levels of each chemical detected are in Figures 3-7. Although chemical levels varied substantially from sample date to sample date, their relative levels from site to site remained somewhat constant. Thus, it was decided that the standard deviation of each mean would be misleading on the graphs. The mean values are used to demonstrate the trends from one site to the next.

The observed men phophate levels (fig. 3) were highest in samples collected from the sites draining Grand Rapids and East Grand Rapids. The levels also declined as water flowed from its source towards the ponds in both inlets. The observed mean ammonia levels (fig. 4) also declined as the water flowed from its source to the ponds in both inputs. The observed mean chloride levels (fig. 5), on the other hand, increased as water flowed from its source to the ponds in both inlets. There no observable trends in the observed mean levels of alkalinity (fig. 6) and hardness (fig. 7).

The mean levels observed of the total inputs to each of the ponds are shown in Figure 8. Observed chloride, hardness, and alkalinity levels are higher in the inputs to Preisdent's Pond. Observed phosphate and ammonia levels, on the other hand, are higher in the inputs to Ravenswood Pond.

DISCUSSION

The levels observed after the first collection date are particularly high (table 1). This date represented the first substantial rainfall in fourteen days (fig. 2). The higher concentrations could be reflected in a build up of chemicals during times of little rain. When larger precipitation events occur after these times the quality of the water is significantly worse.

It is interesting that nitrate was found in any of the samples. Nitrogen was found in the input channels in the form of ammonia. The concentrations of ammonia at sites one and three may have a substantial biological origin. Both sites were observed to support a population of frogs, which release urea and/or ammonia as waste products. Bacteria actively transform urea to ammonia (Nyhof, personal communication).

Due to mild weather conditions, the roads of East Grand Rapids were not treated during the course of the study. It would be predicted that chloride levels ftom site nuniber one would increase throughout the winter and early spring.

The results of this study show relatively higher concentrations of phosphate in the input channels to Ravenswood pond (especially from site number one). This may indicate the over-use of phosphate fertilizers within the East Grand Rapids/ Lake Drive drainage area. Recent study of phosphate content in the sediments of Ravenswood and President's ponds show a high concentration in the substrate immediately surrounding the channel/ pond interface (Post, et al.). The higher levels entering the pond could have had significantly influenced the large fish kill observed at the end of the summer of 1998.

Engineering students from Calvin College have proposed the construction of an artificial wetland to serve as a nutrient trap for the inputs to Ravenswood Pond (Bloom, et al.) This study suggests that such a management plan may be helpful. Results from this study show a significant drop in phosphate concentrations between the origin of the input channels and the point of entry into the ponds. Lengthening the channel length and the retention time of storm water may reduce the amount of phosphate entering the pond.

Future research is needed to fully understand the dynamics of the drainage system in the two ponds. While the concentration of certain chemicals can be directly determined from water samples, the discharge volumes of the input channels are unknown. Thus there is presently no way to quantify the actual amount of any given chemical as it enters the pond system. It is also unknown in what concentrations or amounts nutrients leave the area through the drain located in the south end of President's pond. This particular study focused on three main input channels, and did not sample from private home drainage systems which empty along the perimeter of Ravenswood pond. Another aspect which remains to be investigated is the time lag period between the beginning of a rain event and the activation of the three channels.

LITERATURE CITED:

Bloom, Phil. 1998. (Personal Communication).

Hatch Company Manual. Digital Titrator Model 16900. 1998. Hatch Company.

Nyhof, Richard. 1998 (Personal Communication).

Post, Matt, and Wetzel, Douglas. 1998. Analysis of Sediments in Calvin's Ponds. (Unpublished Report).

FIGURES- click on any figure to see it full size

Figure 1	Figure 2
Figure 3	Figure 4
Figure 5	Figure 6
Figure 7	Figure 8
	for figure 8, ravenswood is on left, president's on right

TABLE 1

The observed values of chemicals analyzed in water collected from five sites in the input channels to President's and Ravenswood ponds during the time period of September 3, '98 to Novemer 10, '98. There was no water avalable to sample at site one on October 17 and samples were not obtained on September 30 and October 1 for sites one, two, and three.